It has been known for sometime to design anti-slip outer soles that are provided with cleats. This has been generally been done in the form of sandals or some type of clip-on device that is attached beneath the sole portion of regular footwear.
Examples of such an item include the following Canadian patents:
CA: 175,047 to Kirkwood Feb. 19, 1917 PA1 (1) a generally planar flexible lower tread element having toe and heel regions corresponding to the toe and heel portions of said footwear; PA1 (2) an elastically extensible, generally planar, upper footwear-contacting, sole element bonded to the upper surface of the tread element; PA1 (3) attachment means, which may be in the form of straps, for attaching the outer sole to the lower surface of the aforesaid footwear,
223,887 to Roe Sep. 19, 1922 PA2 301,313 to Chase Jun. 17, 1930 PA2 398,787 to Lawson Aug. 26, 1941 PA2 527,399 to Smith Jul. 10, 1956 PA2 549,159 to Griffin Nov. 20, 1956 PA2 650,756 to Bailey Oct. 23, 1962 PA2 669,630 to Smith Sep. 3, 1963 PA2 781,673 to Vogt Apr. 2, 1968 All of the foregoing references rely upon either full-sole outer soles, or partial-sole attachments, provided in either case with means for attachment to a regular boot or shoe.
Customarily such attachments are by means of straps. In other cases the attachment means employs toe and/or heel embracing hoods or caps. Where straps are employed, the outer soles are customarily of the sandal-type, wherein the sole is generally planar, and the toe and heel of the wearer's boot are exposed.
The present invention concerns a full-sole outer sole. Such an item of footwear should be light and durable. It should remain firmly in position during use, while being sufficiently pliable to permit a wearer to walk comfortably, in the normal way. These features are present in a sandal-type outer sole that is made from a flexible, resilient material such as rubber.
A problem arises, however, when a thin sandal-type format is adopted for such outer soles. Because the sandal-type sole is preferably thin (to enhance flexibility and reduce weight) and is not attached to the toe or heel of the principal boot by a hood or cap, the sandal-type sole does not readily lie against the wearer's boot. Instead small gaps open, both at the heel and toe while walking.
A problem associated with such gaps is that they tend to collect snow or dirt. This is particularly true at the toe, due to the forward motion of the foot, and the inclined angle of the foot just as it is being picked up to be swung forward.
The accumulation of snow between the outer sole and the boot is irritating for the wearer. Once snow has so accumulated, the foot no longer lies in its natural orientation during walking. Under pressure the accumulated snow may give-way, causing a momentary loss, or irregularity, of support for the wearer's foot. At minimum, this is an anxiety-creating event.
The present invention is directed to providing an outer sole of the sandal-type, for use over pre-existing footwear or boots, that is adapted to minimize the accumulation of snow or dirt between the toe of the boot and the front-end of the outer sole. Provision is also made for the accumulation of snow or dirt at the heel to be minimized. Optionally, such outer soles may be cleated to improve their traction on ice.
The invention in its general form will first be described, and then its implementation in the form of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention will then be further described, and defined, in each of the individual claims which conclude this specification.